body{
    margin: 0 0 0 0;
}

#principal{
	height:auto;
	width:100%;
	position: absolute;
	
}

	#barra_superior{
		height: 25px;
		width: 100%;
		background-image: url(../images/barra.png);
		position: absolute;
	}
	
	#webmail{
		height: 35px;
		width: 117px;
		position: absolute;
		margin-top: 30px;
		left: 70%;
		z-index:1000;
		cursor: pointer;	
	}
		
	#unividas{
		height: 600px;
		width: 962px;
		background-image:url(../images/rectiguazusa2016.gif);
		background-repeat: no-repeat;
		position: relative;
		left:50%;
		margin-left:-481px;
		margin-top: 80px;
	}

	#xadek{
		width: 300px;
		height: 134px;
		background-image:url(../images/logo_xadek.jpg);
		cursor: hand;
		background-repeat: no-repeat;
		position: relative;
		left:50%;
		margin-left:-150px;
		margin-top: 10px;
	}

	#barra_inferior{
		height: 25px;
		width: 100%;
		background-image: url(../images/barra.png);
		position: absolute;
	}